,.

Maria Sovago1, George W H Wurpel, Marc Smits

  • 1FOM Institute for Atomic and Molecular Physics (AMOLF), Kruislaan 407, 1098 SJ, Amsterdam, The Netherlands.

まとめ

カルシウムイオンは,フォスフォリピド単層を大幅に変化させ,低圧では秩序あるドメインを誘導し,中圧では乱れを引き起こします. 高圧下では,カルシウムは膨張し,脂質鎖を構成し,ズウィテリオン性脂質とアニオン性脂質の両方に影響を及ぼします.

関連する概念動画

Calmodulin-dependent Signaling01:16

Calmodulin-dependent Signaling

Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
IP3/DAG Signaling Pathway01:11

IP3/DAG Signaling Pathway

Membrane lipids such as phosphatidylinositol (PI) are precursors for several membrane-bound and soluble second messengers. Specific kinases phosphorylate PI and produce phosphorylated inositol phospholipids. One such inositol phospholipids are the  phosphatidylinositol-4,5 bisphosphate [PI(4,5)P2], present in the inner half of the lipid bilayer. Upon ligand binding, GPCR stimulates Gq proteins to turn on phospholipase Cꞵ. Activated phospholipase Cꞵ cleaves PI(4,5)P2 and produces two-second...
Feedback Regulation of Calcium Concentration01:27

Feedback Regulation of Calcium Concentration

Calcium is an essential signaling molecule required for various cellular functions. Calcium pumps and ion channels on cell and organellar membranes, such as those on the endoplasmic reticulum (ER), regulate calcium concentrations inside the cell. They remain closed, keeping the cytosolic calcium levels low at a resting state.
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Assembly of the Lipid Bilayer in the ER01:28

Assembly of the Lipid Bilayer in the ER

Biological membranes are more than just a barrier separating cell cytoplasm from the outside environment. They are highly dynamic and help maintain the integrity and physiological stability of the cells as well as membrane-bound organelles. Membranes also play vital roles in cell-to-cell and intracellular communication.
A large chunk of any biological membrane is composed of phospholipids. These lipids have a heterogeneous distribution across different subcellular organelles and even between...
Phosphoinositides and PIPs01:42

Phosphoinositides and PIPs

Phosphoinositides are a group of phospholipids containing a glycerol backbone with two fatty acid chains and a phosphate attached to a myoinositol sugar ring. The inositol head group extends into the cytoplasm, where it is modified by adding phosphate groups to form phosphatidylinositol phosphates or PIPs.
Different phosphoinositides are synthesized and recruited on the cytosolic face of the plasma membrane. The localization of specific phosphoinositides concentrated in separate membrane...
Asymmetric Lipid Bilayer01:35

Asymmetric Lipid Bilayer

Biological membranes show uneven distribution of different types of lipids in the inner and outer layers, resulting in transverse asymmetric membranes. The treatment of the erythrocyte membrane with the enzyme phospholipase confirmed the asymmetric nature of the lipid bilayer. The enzyme hydrolyzes lipids into fatty acids and hydrophilic groups. The phospholipase acts only on the outer layer of the membrane, while the inner layer remains intact. The phospholipase treatment resulted in 80%...